Materials gradient within armor for balancing the ballistic performance

ABSTRACT

Hybrid, multi-panel ballistic resistant articles useful for the fabrication of body armor. The articles include at least three different fabric sections that are arranged into a gradient wherein the outermost, strike-face section of the article is formed from fibers having the highest tenacity of the article.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending U.S. application Ser. No.14/851,875, filed Sep. 11, 2015, which claims the benefit of U.S.Provisional Application Ser. No. 62/088,015, filed on Dec. 5, 2014, thedisclosures of which are incorporated by reference herein in theirentireties.

BACKGROUND Technical Field

This technology relates to ballistic resistant composite articles havingimproved backface deformation resistance as well as superior ballisticpenetration resistance. Particularly, this technology relates to hybrid,multi-panel ballistic resistant articles that are especially useful forthe fabrication of body armor.

Description of the Related Art

Ballistic resistant articles such as bullet resistant vests, helmets,vehicle panels and structural members of military equipment aretypically made from composite armor comprising high strength fibers.High strength fibers conventionally used to fabricate composite armorinclude polyethylene fibers, aramid fibers such as poly(phenylenediamineterephthalamide), graphite fibers, nylon fibers, glass fibers and thelike. For some applications, the fibers are formed into woven or knittedfabrics. For other applications, the fibers are coated with a polymericbinder material and formed into non-woven fabrics.

Various ballistic resistant constructions are known that are useful forthe formation of hard or soft body armor articles such as helmets andvests. For example, U.S. Pat. Nos. 4,403,012, 4,457,985, 4,613,535,4,623,574, 4,650,710, 4,737,402, 4,748,064, 5,552,208, 5,587,230,6,642,159, 6,841,492, 6,846,758, all of which are incorporated herein byreference, describe ballistic resistant composites which include highstrength fibers made from materials such as extended chain ultra-highmolecular weight polyethylene (UHMW PE). These composites displayvarying degrees of ballistic resistance to high speed projectiles suchas bullets, shells, shrapnel and the like.

The two primary measures of anti-ballistic performance of compositearmor are ballistic penetration resistance and blunt trauma (“trauma”)resistance. A common characterization of ballistic penetrationresistance is the V₅₀ velocity, which is the experimentally derived,statistically calculated impact velocity at which a projectile isexpected to completely penetrate armor 50% of the time and be completelystopped by the armor 50% of the time. For composites of equal arealdensity (i.e. the weight of the composite armor divided by the surfacearea) the higher the V₅₀ the better the penetration resistance of thecomposite. In this regard, it is known that the V₅₀ ballisticperformance of fibrous composite armor is directly related to thestrength of the constituent fibers of the composite.

Whether or not a high speed projectile penetrates armor, when theprojectile engages the armor the impact also deflects the body armor atthe area of impact, potentially causing significant non-penetrating,blunt trauma injuries. The measure of the depth of deflection of bodyarmor due to a bullet impact is known as backface signature (“BFS”),also known in the art as backface deformation or trauma signature.Potentially resulting blunt trauma injuries may be as deadly to anindividual as if the bullet had fully penetrated the armor and enteredthe body. This is especially consequential in the context of helmetarmor, where the transient protrusion caused by a stopped bullet canstill cross the plane of the skull underneath the helmet and causedebilitating or fatal brain damage. Accordingly, there is a need in theart for ballistic resistant composites having both superior V₅₀ballistic performance as well as low backface signature.

This disclosure provides a solution to this need. Particularly, it hasbeen unexpectedly found that body armor having excellent ballisticpenetration resistance performance and backface signature performancecan be achieved at a lower cost by combining multiple different sectionsof materials. The sections are arranged into a gradient wherein theoutermost, strike-face section of the article is formed from fibershaving the highest tenacity of the article, and the outermost section onthe opposite side of the article will be formed from the lowest tenacityfibers of the article or from no fibers at all. In this regard, eachsection of the composite article performs a different function. Thefirst, outermost strike-face section of fibrous plies functions to breakopen the metal casing of a bullet, such as a 9 mm Full Metal Jacket(FMJ) bullet which comprises a lead core portion covered by a coppercasing (jacket). Breaking open of the casing will thereby expose thelead core. The second section of fibrous plies will then deform anyremaining portion of the casing material as well as the bullet corematerial and also reduce the velocity of the deformed parts and anyprojectile fragments. The third section will then distribute theremaining kinetic energy of the bullet over a large area and thus reducethe trauma energy transmitted to the user of the armor. Together, thedifferent sections of material provide excellent ballistic penetrationresistance and trauma resistance.

SUMMARY

Provided is a ballistic resistant composite comprising:

a first fibrous material comprising one or more first fibrous plies,each of the first fibrous plies comprising fibers that have a tenacityof greater than 27 g/denier;

a second fibrous material attached to the first fibrous material, saidsecond fibrous material comprising one or more second fibrous plies,each of the second fibrous plies comprising fibers that have a tenacitylower than the tenacity of the fibers of the first fibrous material; and

a third fibrous material attached to the second fibrous material, saidthird fibrous material comprising one or more third fibrous plies, eachof the third fibrous plies comprising fibers that have a tenacity lowerthan the tenacity of the fibers of the second fibrous material;

wherein the first fibrous material, second fibrous material and thirdfibrous material are bonded together and form a consolidated, unitarycomposite article.

Further provided is a ballistic resistant composite comprising:

a first fibrous material comprising one or more first fibrous plies,each of the first fibrous plies comprising fibers;

a second fibrous material attached to the first fibrous material, saidsecond fibrous material comprising one or more second fibrous plies,each of the second fibrous plies comprising fibers that have a tenacitylower than the tenacity of the fibers of the first fibrous material; and

a non-fibrous sheet material attached to the second fibrous material;

wherein the first fibrous material, second fibrous material and thirdfibrous material are bonded together and form a consolidated, unitarycomposite article.

Also provided is a ballistic resistant composite comprising:

a first fibrous material comprising one or more first fibrous plies,each of the first fibrous plies comprising fibers, wherein each of saidfibers has a tenacity of greater than 27 g/denier;

a second fibrous material attached to the first fibrous material, saidsecond fibrous material comprising one or more second fibrous plies,each of the second fibrous plies comprising fibers, wherein each of saidfibers has a tenacity of at least 50% less than the tenacity of thefibers of the first fibrous material; and

a third fibrous material attached to the second fibrous material, saidthird fibrous material comprising one or more third fibrous plies, eachof the third fibrous plies comprising fibers, wherein each of saidfibers has a tenacity of at least 50% less than the tenacity of thefibers of the second fibrous material;

wherein the first fibrous material, second fibrous material and thirdfibrous material are bonded together and form a consolidated, unitarycomposite article.

DETAILED DESCRIPTION

The composites provided herein include three or more different sections,at least two of the sections comprising a plurality of fibrous plies.Each of the fibrous plies comprises a plurality of fibers and optionallya polymeric binder material on the fibers. A first fibrous materialhaving first and second surfaces is positioned as the strike facesection of the composite, i.e. the outermost section that a projectilethreat will strike first. The projectile will first contact the firstsurface of the first fibrous material. A second fibrous material havingfirst and second surfaces is attached to the second surface of the firstfibrous material. A third section having first and second surfaces isattached to the second surface of the second fibrous material. The thirdsection may be a fibrous material comprising fibers or may be anon-fibrous material, such as a non-fibrous sheet.

Most or all of the fibers forming the first fibrous material and thesecond fibrous material are high strength fibers, with the first fibrousmaterial comprising stronger fibers, i.e. fibers having a highertenacity, than the fibers forming the second fibrous material. As usedherein, a “high strength fiber” fiber is one which has a minimumtenacity of at least 7 g/denier, a preferred tensile modulus of at leastabout 150 g/denier, and preferably an energy-to-break of at least about8 J/g, each as measured by ASTM D2256. However, the fibers forming eachof the first fibrous material and the second fibrous material aresubstantially greater than 7 g/denier, and most or all of the fibersforming the first fibrous material are substantially greater than thefibers forming the second fibrous material. By “most or all” it is meantthat more than 50% of the fibers forming the first fibrous material havea tenacity that is greater than the tenacity of at least 50% of thefibers forming the second fibrous material. In more preferredembodiments, at least 75% of the fibers forming the first fibrousmaterial have a tenacity that is greater than the tenacity of at least75% of the fibers forming the second fibrous material. In still morepreferred embodiments, at least 95% of the fibers forming the firstfibrous material have a tenacity that is greater than the tenacity of atleast 95% of the fibers forming the second fibrous material. Mostpreferably, all of the fibers of the first fibrous material are fibershaving a tenacity greater than all of the fibers of the second fibrousmaterial. In this regard, the fibers forming each of the first fibrousmaterial and the second fibrous material are exclusive of fibers orthreads employed to stitch or sew together any of the fibrous plies orsections. Accordingly, the first fibrous material by itself hassignificantly greater ballistic penetration resistance than the secondfibrous material by itself.

When the third section comprises fibers, it is referred to herein as athird fibrous material. In accordance with the preferred embodiments,more than 50% of the fibers forming the second fibrous material have atenacity that is greater than the tenacity of at least 50% of the fibersforming the third fibrous material. In more preferred embodiments, atleast 75% of the fibers forming the second fibrous material have atenacity that is greater than the tenacity of at least 75% of the fibersforming the third fibrous material. In still more preferred embodiments,at least 95% of the fibers forming the second fibrous material have atenacity that is greater than the tenacity of at least 95% of the fibersforming the third fibrous material. Most preferably, all of the fibersof the second fibrous material are fibers having a tenacity greater thanall of the fibers of the third fibrous material. Accordingly, the boththe first fibrous material and the second fibrous material individuallyhave significantly greater ballistic penetration resistance than thethird fibrous material individually, and as stated above, the fibersforming each of the first fibrous material, second fibrous material andthird fibrous material are exclusive of fibers or threads employed tostitch or sew together a plurality of fibrous plies or sections.

In accordance with this objective, each of the fibers of the secondfibrous material preferably has a tenacity of at least 25% less than thetenacity of the fibers of the first fibrous material, and each of thefibers of the optional third fibrous material preferably has a tenacityof at least 25% less than the tenacity of the fibers of the secondfibrous material. In further accordance with this objective, it ispreferred that each of the fibers forming the fibrous plies of the firstfibrous material (i.e. the first fibrous plies) are preferably fibershaving a tenacity of greater than 27 g/denier, more preferably atenacity of from about 28 g/denier to about 60 g/denier, still morepreferably from about 33 g/denier to about 60 g/denier, still morepreferably 39 g/denier or more, still more preferably from at least 39g/denier to about 60 g/denier, still more preferably 40 g/denier ormore, still more preferably 43 g/denier or more, or at least 43.5g/denier, still more preferably from about 45 g/denier to about 60g/denier, still more preferably at least 45 g/denier, at least about 48g/denier, at least about 50 g/denier, at least about 55 g/denier or atleast about 60 g/denier. Each of the fibers forming the fibrous plies ofthe second fibrous material (i.e. the second fibrous plies) arepreferably fibers having a tenacity of from about 20 g/denier to about45 g/denier, more preferably from about 20 g/denier to about 40g/denier, still more preferably from about 20 g/denier to about 35g/denier, and most preferably from about 20 g/denier to about 30g/denier. However, the fibers of said second fiber plies may be higherdepending on the tenacity of the fibers forming the first fibrous plies.

In embodiments where the third section is a third fibrous material, eachof the fibers forming the fibrous plies of said third fibrous material(i.e. the third fibrous plies) are preferably fibers having a tenacityof from about 3 g/denier to about 34 g/denier (e.g. 33.75 g/d (25% of 45g/d)), more preferably from about 5 g/denier to about 30 g/denier, stillmore preferably from about 5 g/denier to about 25 g/denier, still morepreferably from about 5 g/denier to about 20 g/denier, still morepreferably from about 5 g/denier to about 15 g/denier, and still morepreferably from about 5 g/denier to about 10 g/denier. However, thefibers of said third fiber plies may be lower or higher. For example, inone embodiment, the third fibrous material comprises fibers having atenacity of less than 7 g/denier, less than 6 g/denier or less than 5g/denier.

In more preferred embodiments, each of the fibers of the second fibrousmaterial preferably has a tenacity of at least 35% less than thetenacity of the fibers of the first fibrous material, and each of thefibers of the optional third fibrous material preferably has a tenacityof at least 35% less than the tenacity of the fibers of the secondfibrous material. Still more preferably, each of the fibers of thesecond fibrous material preferably has a tenacity of at least 50% lessthan the tenacity of the fibers of the first fibrous material, and eachof the fibers of the optional third fibrous material preferably has atenacity of at least 50% less than the tenacity of the fibers of thesecond fibrous material. In these embodiments, the fiber types formingeach fibrous material section may be the same as or different than thefiber types forming the other fibrous material sections. It is alsowithin the scope of the invention that the fibers of the second fibrousmaterial may be only 10% less or from about 10% to about 25% less, orfrom about 25% less to about 50% less than the tenacity of the fibers ofthe first fibrous material, and the fibers of the third fibrous materialmay be only 10% less or from about 10% to about 25% less, or from about25% less to about 50% less than the tenacity of the fibers of the secondfibrous material, but at least a 25% difference is most preferred.

Additionally, while it is preferred that “each” of the fibers in aparticular fibrous material section has a different tenacity than “each”of the fibers in “each” adjacent fibrous material section, one or moreof the fibrous material sections may include a small portion of fibers(e.g. less than 10%) having other tenacities that may be the same as oneor more of the other sections, as long as most of the fibers (i.e. >50%,≥60%, ≥70%, ≥80%, ≥90%; ≥95%; ≥98%; or ≥99%) in each consecutive fibrousmaterial section, beginning at the first, strike face section, havetenacities that are at least 10% greater, more preferably at least 25%greater, than the previous fibrous material section. For example, thesecond fibrous material section may optionally include a small portionof fibers/filaments, preferably less than 10% of the total number offibers/filaments in the section, that have the same tenacity or agreater tenacity than the fibers in the first fibrous material section,or that have the same tenacity or a lower tenacity than fibers a thirdfibrous section. This, however, is not preferred. Any overlap in theabove specified tenacity ranges still require the that the other fibertenacity requirements of the fibrous material sections be met, i.e. ifthe fibers of the first fibrous material section (i.e. >50%, ≥60%, ≥70%,≥80%, ≥90%; ≥95%; ≥98%; or ≥99%, or 100% of the fibers) have a tenacityof 28 g/denier, the fibers of the first fibrous material section(i.e. >50%, ≥60%, ≥70%, ≥80%, ≥90%; ≥95%; ≥98%; or ≥99%, or 100% of thefibers) should have tenacities of at least 25% less than 28 g/denier,i.e. 21 g/denier or less. Most preferably all the fibers forming eachrespective individual (single) fibrous ply and individual (single)fibrous layer are identical to each other in polymer type, chemicalcomposition and tenacity, and most preferably all the fibers forming asingle fibrous material section are identical to each other in polymertype, chemical composition and tenacity. Accordingly, a fibrous materialsection is most clearly distinguished from other fibrous materialsections by the differences in the component fibers forming eachrespective section, particularly the tenacity of the fibers in thedifferent sections.

The fibers forming the fibrous plies of the each of the first fibrousmaterial, second fibrous material and optional third fibrous materialmay vary depending on the desired tensile properties for each material.Particularly suitable high tenacity fibers include polyolefin fibers,such as high molecular weight polyethylene fibers, particularlyultra-high molecular weight polyethylene fibers, and polypropylenefibers. Also suitable are aramid fibers, particularly para-aramidfibers, polyamide fibers, polyethylene terephthalate fibers,polyethylene naphthalate fibers, extended chain polyvinyl alcoholfibers, extended chain polyacrylonitrile fibers, polybenzoxazole (PBO)fibers, polybenzothiazole (PBT) fibers, liquid crystal copolyesterfibers, rigid rod fibers such as M5® fibers, and glass fibers, includingelectric grade fiberglass (E-glass; low alkali borosilicate glass withgood electrical properties), structural grade fiberglass (S-glass; ahigh strength magnesia-alumina-silicate) and resistance grade fiberglass(R-glass; a high strength alumino silicate glass without magnesium oxideor calcium oxide). Each of these fiber types is conventionally known inthe art. Also suitable for producing polymeric fibers are copolymers,block polymers and blends of the above materials.

The most preferred fiber types for the first fibrous material and secondfibrous material are high performance fibers including polyethylenefibers (particularly extended chain polyethylene fibers), aramid fibers,PBO fibers, liquid crystal copolyester fibers, polypropylene fibers(particularly highly oriented extended chain polypropylene fibers),polyvinyl alcohol fibers, polyacrylonitrile fibers, glass fibers andrigid rod fibers, particularly M5® rigid rod fibers. Specifically mostpreferred are polyethylene fibers and aramid fibers. The fibers formingeach of the first fibrous material and second fibrous material may bethe same fiber type or may be different fiber types. When the fibersforming the first fibrous material and second fibrous material are thesame fiber type (e.g. both comprise, consist of or consist essentiallyof polyethylene fibers, or both comprise, consist of or consistessentially of aramid fibers) the fibers of the second fibrous materialmust still have a lower tenacity than the fibers of the first fibrousmaterial, preferably at least 25% less, more preferably at least 35%less, most preferably at least 50% less than the tenacity of the fibersof the first fibrous material.

In the case of polyethylene, preferred fibers are extended chainpolyethylenes having molecular weights of at least 300,000, preferablyat least one million and more preferably between two million and fivemillion. Such extended chain polyethylene (ECPE) fibers may be grown insolution spinning processes such as described in U.S. Pat. Nos.4,137,394 or 4,356,138, which are incorporated herein by reference, ormay be spun from a solution to form a gel structure, such as describedin U.S. Pat. Nos. 4,413,110; 4,536,536; 4,551,296; 4,663,101; 5,006,390;5,032,338; 5,578,374; 5,736,244; 5,741,451; 5,958,582; 5,972,498;6,448,359; 6,746,975; 6,969,553; 7,078,099; 7,344,668 and U.S. patentapplication publication 2007/0231572, all of which are incorporatedherein by reference. Particularly preferred fiber types are any of thepolyethylene fibers sold under the trademark SPECTRA® from HoneywellInternational Inc. SPECTRA® fibers are well known in the art. Otheruseful polyethylene fiber types also include and DYNEEMA® UHMW PE yarnscommercially available from Royal DSM N.V. Corporation of Heerlen, TheNetherlands.

Particularly preferred methods for forming UHMW PE fibers are processesthat are capable of producing UHMW PE fibers having tenacities of atleast 39 g/denier, most preferably where the fibers are multi-filamentfibers. The most preferred processes include those described incommonly-owned U.S. Pat. Nos. 7,846,363; 8,361,366; 8,444,898;8,747,715; as well as U.S. publication no. 2011-0269359, the disclosuresof which are incorporated by reference herein to the extent consistentherewith. Such processes are called “gel spinning” processes, alsoreferred to as “solution spinning,” wherein a solution of ultra highmolecular weight polyethylene and a solvent is formed, followed byextruding the solution through a multi-orifice spinneret to formsolution filaments, cooling the solution filaments into gel filaments,and extracting the solvent to form dry filaments. These dry filamentsare grouped into bundles which are referred to in the art as eitherfibers or yarns. The fibers/yarns are then stretched (drawn) up to amaximum drawing capacity to increase their tenacity.

Preferred aramid (aromatic polyamide) fibers are well known andcommercially available, and are described, for example, in U.S. Pat. No.3,671,542. For example, useful aramid filaments are producedcommercially by DuPont under the trademark of KEVLAR®. Also usefulherein are poly(m-phenylene isophthalamide) fibers produced commerciallyby DuPont of Wilmington, Del. under the trademark NOMEX® and fibersproduced commercially by Teijin Aramid Gmbh of Germany under thetrademark TWARON®; aramid fibers produced commercially by KolonIndustries, Inc. of Korea under the trademark HERACRON®; p-aramid fibersSVM™ and RUSAR™ which are produced commercially by Kamensk Volokno JSCof Russia and ARMOS™ p-aramid fibers produced commercially by JSC ChimVolokno of Russia.

Suitable PBO fibers are commercially available and are disclosed forexample in U.S. Pat. Nos. 5,286,833, 5,296,185, 5,356,584, 5,534,205 and6,040,050, each of which is incorporated herein by reference. Suitableliquid crystal copolyester fibers are commercially available and aredisclosed, for example, in U.S. Pat. Nos. 3,975,487; 4,118,372 and4,161,470, each of which is incorporated herein by reference, andincluding VECTRAN® liquid crystal copolyester fibers commerciallyavailable from Kuraray Co., Ltd. of Tokyo, Japan. Suitable polypropylenefibers include highly oriented extended chain polypropylene (ECPP)fibers as described in U.S. Pat. No. 4,413,110, which is incorporatedherein by reference. Suitable polyvinyl alcohol (PV-OH) fibers aredescribed, for example, in U.S. Pat. Nos. 4,440,711 and 4,599,267 whichare incorporated herein by reference. Suitable polyacrylonitrile (PAN)fibers are disclosed, for example, in U.S. Pat. No. 4,535,027, which isincorporated herein by reference. Each of these fiber types isconventionally known and is widely commercially available. M5® fibersare formed from pyridobisimidazole-2,6-diyl (2,5-dihydroxy-p-phenylene)and were most recently manufactured by Magellan Systems International ofRichmond, Va. and are described, for example, in U.S. Pat. Nos.5,674,969, 5,939,553, 5,945,537, and 6,040,478, each of which isincorporated herein by reference. The term “rigid rod” fibers is notlimited to such pyridobisimidazole-based fiber types, and many PBO andaramid fiber varieties are often referred to as rigid rod fibers.Commercially available glass fibers include S2-Glass® S-glass fiberscommercially available from AGY of Aiken, S.C., HiPerTex™ E-Glassfibers, commercially available from 3B Fibreglass of Battice, Belgium,and VETROTEX® R-glass fibers from Saint-Gobain of Courbevoie, France.

The fibers forming a third fibrous material may or may not be formedfrom high performance fibers, but as noted previously the fibers of thethird fibrous material will have tenacities lower than each of the firstfibrous material and second fibrous material, preferably comprisingfibers having tenacities at least 25% less than the fibers forming thesecond fibrous material. Suitable fibers for forming the third fibrousmaterial non-exclusively include nylon fibers, polyester fibers,polypropylene fibers, polyolefin fibers or a combination thereof,preferably having tenacities from about 5 g/denier to about 20 g/denier,more preferably from about 5 g/denier to about 15 g/denier, and stillmore preferably from about 5 g/denier to about 10 g/denier. Higher orlower tenacity fibers are also useful provided that their tenacities arelower than the fibers of the second fibrous plies. In this regard,fibers such as nylon fibers, polyester fibers, polypropylene fibers orpolyolefin fibers, or a combination thereof, which have tenacities ofless than 5 g/denier are also useful herein. Of these fiber types, nylonfibers are most preferred, particularly 420 denier or 840 denier nylonfibers and fabrics formed therefrom, which are widely commerciallyavailable. A particularly preferred third fibrous material sectioncomprises a woven fabric formed from 840 denier nylon fibers, such aswoven fabrics having a 26×26 plain weave construction and an arealdensity of 200 g/m², which is commercially available. Also suitable areCORDURA® brand nylon fabrics commercially available from Invista NorthAmerica S.A R.L. of Wilmington, Del. Particularly preferred nylon fibersare nylon 6 fibers, nylon 6,6 fibers and nylon 4,6 fibers.

Alternatively, the third section may be a non-fibrous material, such asa polymer sheet, a metal sheet or an energy mitigating material such asa foam. Preferred polymer sheets include one or more isotropic polymerlayers, which are isotropic in regard to their physical properties.Suitable isotropic polymer layers may be formed from polymers such asacrylics, nylons (such as nylon 6; nylon 6,6; or nylon 4,6),polyolefins, epoxies, silicones, polyesters, polycarbonate or polyvinylchlorides, but this list is non-exclusive. Methods of making isotropicpolymer layers are conventionally known. Suitable metal sheetsnon-exclusively include high hardness steel (HHS), aluminum alloys,titanium or a combination thereof. Suitable open-cell foamsnon-exclusively include polyurethane foams, polyethylene foams,polyvinyl chloride (PVC) foams, and other thermoplastic resin foams.Polyurethane foams are the most common. Open-cell foams are commerciallyavailable and are described, for example, in U.S. Pat. Nos. 6,174,741,6,093,752, 5,824,710, 5,114,773 and 4,957,798, the disclosures of whichare incorporated herein by reference. Foams are also described in thepublication Handbook of Plastic Foams, by Arthur H. Landrock, NovesPublication (1995). Foam raw material manufacturers include The DowChemical Company of Midland, Mich. and Bayer Corporation of Pittsburgh,Pa. Foam converters (from liquid to flexible foams) include AmericanExcelsior Corp. of Texas, Foamtech Corporation of Massachusetts, Wis.Foam Products of Wisconsin, UFP Technologies of Massachusetts, SealedAir Corporation of N.J. and McMaster-Carr of Robbinsville, N.J. Rigid,closed-cell foams may also be used, such as such as a vinyl nitrile(e.g., polyvinylchloride (PVC) nitrile) foam, a polyethylene foam, or anethylene vinyl acetate foam. Examples of suitable commercially availableclosed cell foams are neoprene/EPDM/SBr (neoprene/ethylene propylenediene monomer/styrene-butadiene rubber) closed cell foams commerciallyavailable from McMaster-Carr of Robbinsville, N.J.; United Foam XRD 15PCF polyethylene commercially available from UFP Technologies ofRaritan, N.J. (manufactured by Qycell Corporation of Ontario, CA). The“Adhesive Backed Open Cell Foam” used in Comparative Examples 7-9 was a0.25 inch thick water-resistant, super-cushioning open cell polyurethanefoam with an adhesive backing, commercially available fromMcMaster-Carr.

For the purposes of the present invention, a “fiber” is an elongate bodythe length dimension of which is much greater than the transversedimensions of width and thickness. The cross-sections of fibers for usein this invention may vary widely, and they may be circular, flat oroblong in cross-section. They also may be of irregular or regularmulti-lobal cross-section having one or more regular or irregular lobesprojecting from the linear or longitudinal axis of the filament. Thusthe term “fiber” includes filaments, ribbons, strips and the like havingregular or irregular cross-section. It is preferred that the fibers havea substantially circular cross-section. As used herein, the term “yarn”is defined as a single strand consisting of multiple fibers. A singlefiber may be formed from just one filament or from multiple filaments. Afiber formed from just one filament is referred to herein as either a“single-filament” fiber or a “monofilament” fiber, and a fiber formedfrom a plurality of filaments is referred to herein as a “multifilament”fiber. The term “denier” is a unit of linear density equal to the massin grams per 9000 meters of fiber/yarn. In this regard, the fibers maybe of any suitable denier. For example, fibers may have a denier of fromabout 50 to about 5000 denier, more preferably from about 200 to 5000denier, still more preferably from about 650 to about 3000 denier, andmost preferably from about 800 to about 1500 denier. The selection isgoverned by considerations of ballistic effectiveness and cost. Finerfibers are more costly to manufacture and to weave, but can producegreater ballistic effectiveness per unit weight.

The “tenacity” of a fiber refers to the tensile stress expressed asforce (grams) per unit linear density (denier) of an unstressedspecimen. The term “fibrous ply” as used herein refers to a single arrayof unidirectionally oriented fibers, a single woven fabric, a singleknitted fabric or a single felted fabric. Each fibrous ply will haveboth an outer top surface and an outer bottom surface and a plurality of“fibrous plies” describes more than one ply of the fibrous structures. Asingle fibrous ply of unidirectionally oriented fibers comprises anarrangement of fibers that are aligned in a unidirectional,substantially parallel array. This type of fiber arrangement is alsoknown in the art as a “unitape”, “unidirectional tape”, “UD” or “UDT.”As used herein, an “array” describes an orderly arrangement of fibers oryarns, which is exclusive of woven and knitted fabrics, and a “parallelarray” describes an orderly, side-by-side, coplanar parallel arrangementof fibers or yarns. The term “oriented” as used in the context of“oriented fibers” refers to the alignment direction of the fibers ratherthan to stretching of the fibers. The term “fabric” describes structuresthat may include one or more fiber plies, with or withoutconsolidation/molding of the plies. A non-woven fabric formed fromunidirectional fibers typically comprises a plurality of non-woven fiberplies that are stacked on each other surface-to-surface in asubstantially coextensive fashion and consolidated. When used herein, a“single-layer” structure refers to any monolithic fibrous structurecomposed of one or more individual plies, wherein multiple plies havebeen merged by consolidation or molding techniques. The term “composite”refers to combinations of fibers, optionally but preferably with apolymeric binder material.

The fibers forming each composite of the invention are preferably, butnot necessarily, at least partially coated with a polymeric bindermaterial. The polymeric binder material is also commonly referred to inthe art as a polymeric “matrix” material. These terms are conventionallyknown in the art and describe a material that binds fibers together,either by way of its inherent adhesive characteristics or after beingsubjected to well known heat and/or pressure conditions. As used herein,a “polymeric” binder or matrix material includes resins and rubber. Whenpresent, the polymeric binder/matrix material either partially orsubstantially coats the individual fibers, preferably substantiallycoating each of the individual filaments/fibers forming a fiber ply orfiber layer.

Suitable polymeric binder materials include both low tensile modulus,elastomeric materials and high tensile modulus, rigid materials. As usedherein throughout, the term tensile modulus means the modulus ofelasticity, which for polymeric binder materials is measured by ASTMD638. A low or high modulus binder may comprise a variety of polymericand non-polymeric materials. For the purposes of this invention, a lowmodulus elastomeric material has a tensile modulus measured at about6,000 psi (41.4 MPa) or less according to ASTM D638 testing procedures.A low modulus polymer is preferably an elastomer having a tensilemodulus of about 4,000 psi (27.6 MPa) or less, more preferably about2400 psi (16.5 MPa) or less, still more preferably 1200 psi (8.23 MPa)or less, and most preferably is about 500 psi (3.45 MPa) or less. Theglass transition temperature (Tg) of the low modulus elastomericmaterial is preferably less than about 0° C., more preferably the lessthan about −40° C., and most preferably less than about −50° C. The lowmodulus elastomeric material also has a preferred elongation to break ofat least about 50%, more preferably at least about 100% and mostpreferably at least about 300%. Whether a low modulus material or a highmodulus material, the polymeric binder may also include fillers such ascarbon black or silica, may be extended with oils, or may be vulcanizedby sulfur, peroxide, metal oxide or radiation cure systems as is wellknown in the art.

A wide variety of materials and formulations may be utilized as a lowmodulus polymeric binder. Representative examples include polybutadiene,polyisoprene, natural rubber, ethylene-propylene copolymers,ethylene-propylene-diene terpolymers, polysulfide polymers, polyurethaneelastomers, chlorosulfonated polyethylene, polychloroprene, plasticizedpolyvinylchloride, butadiene acrylonitrile elastomers,poly(isobutylene-co-isoprene), polyacrylates, polyesters, polyethers,fluoroelastomers, silicone elastomers, copolymers of ethylene,polyamides (useful with some fiber types), acrylonitrile butadienestyrene, polycarbonates, and combinations thereof, as well as other lowmodulus polymers and copolymers curable below the melting point of thefiber. Also useful are blends of different elastomeric materials, orblends of elastomeric materials with one or more thermoplastics.

Particularly useful are block copolymers of conjugated dienes and vinylaromatic monomers. Butadiene and isoprene are preferred conjugated dieneelastomers. Styrene, vinyl toluene and t-butyl styrene are preferredconjugated aromatic monomers. Block copolymers incorporatingpolyisoprene may be hydrogenated to produce thermoplastic elastomershaving saturated hydrocarbon elastomer segments. The polymers may besimple tri-block copolymers of the type A-B-A, multi-block copolymers ofthe type (AB)_(n) (n=2-10) or radial configuration copolymers of thetype R-(BA)_(x) (x=3-150); wherein A is a block from a polyvinylaromatic monomer and B is a block from a conjugated diene elastomer.Many of these polymers are produced commercially by Kraton Polymers ofHouston, Tex. and described in the bulletin “Kraton ThermoplasticRubber”, SC-68-81. Also useful are resin dispersions ofstyrene-isoprene-styrene (SIS) block copolymer sold under the trademarkPRINLIN® and commercially available from Henkel Technologies, based inDusseldorf, Germany. Conventional low modulus polymeric binder polymersemployed in ballistic resistant composites includepolystyrene-polyisoprene-polystyrene block copolymers sold under thetrademark KRATON® commercially produced by Kraton Polymers.

While low modulus polymeric binder materials are preferred for theformation of flexible armor materials, high modulus polymeric bindermaterials are preferred for the formation of rigid armor articles. Highmodulus, rigid materials generally have an initial tensile modulusgreater than 6,000 psi. Useful high modulus, rigid polymeric bindermaterials include polyurethanes (both ether and ester based), epoxies,polyacrylates, phenolic/polyvinyl butyral (PVB) polymers, vinyl esterpolymers, styrene-butadiene block copolymers, as well as mixtures ofpolymers such as vinyl ester and diallyl phthalate or phenolformaldehyde and polyvinyl butyral. A particularly useful rigidpolymeric binder material is a thermosetting polymer that is soluble incarbon-carbon saturated solvents such as methyl ethyl ketone, andpossessing a high tensile modulus when cured of at least about 1×10⁶ psi(6895 MPa) as measured by ASTM D638. Particularly useful rigid polymericbinder materials are those described in U.S. Pat. No. 6,642,159, thedisclosure of which is incorporated herein by reference.

Most specifically preferred are polar resins or polar polymers,particularly polyurethanes within the range of both soft and rigidmaterials at a tensile modulus ranging from about 2,000 psi (13.79 MPa)to about 8,000 psi (55.16 MPa). Preferred polyurethanes are applied asaqueous polyurethane dispersions that are most preferably, but notnecessarily, cosolvent free. Such includes aqueous anionic polyurethanedispersions, aqueous cationic polyurethane dispersions and aqueousnonionic polyurethane dispersions. Particularly preferred are aqueousanionic polyurethane dispersions; aqueous aliphatic polyurethanedispersions, and most preferred are aqueous anionic, aliphaticpolyurethane dispersions, all of which are preferably cosolvent freedispersions. Such includes aqueous anionic polyester-based polyurethanedispersions; aqueous aliphatic polyester-based polyurethane dispersions;and aqueous anionic, aliphatic polyester-based polyurethane dispersions,all of which are preferably cosolvent free dispersions. Such alsoincludes aqueous anionic polyether polyurethane dispersions; aqueousaliphatic polyether-based polyurethane dispersions; and aqueous anionic,aliphatic polyether-based polyurethane dispersions, all of which arepreferably cosolvent free dispersions. Similarly preferred are allcorresponding variations (polyester-based; aliphatic polyester-based;polyether-based; aliphatic polyether-based, etc.) of aqueous cationicand aqueous nonionic dispersions. Most preferred is an aliphaticpolyurethane dispersion having a modulus at 100% elongation of about 700psi or more, with a particularly preferred range of 700 psi to about3000 psi. More preferred are aliphatic polyurethane dispersions having amodulus at 100% elongation of about 1000 psi or more, and still morepreferably about 1100 psi or more. Most preferred is an aliphatic,polyether-based anionic polyurethane dispersion having a modulus of 1000psi or more, preferably 1100 psi or more.

When a composite does include a binder, the total weight of the bindercomprising the composite preferably comprises from about 2% to about 50%by weight, more preferably from about 5% to about 30%, more preferablyfrom about 7% to about 20%, and most preferably from about 11% to about16% by weight of the fibers plus the weight of the binder. A lowerbinder content is appropriate for woven and knitted fabrics, wherein apolymeric binder content of greater than zero but less than 10% byweight of the fibers plus the weight of the binder is typically mostpreferred, but this is not intended as strictly limiting. For example,phenolic/PVB impregnated woven aramid fabrics are sometimes fabricatedwith a higher resin content of from about 20% to about 30%, althoughabout 12% content is typically preferred. Typically, weaving or knittingof fabrics is performed prior to coating the fibers with an optionalpolymeric binder, wherein the fabrics are thereafter impregnated withthe binder.

Methods for applying a polymeric binder material to fibers to therebyimpregnate fiber plies/layers with the binder are well known and readilydetermined by one skilled in the art. The term “impregnated” isconsidered herein as being synonymous with “embedded,” “coated,” orotherwise applied with a polymeric coating where the binder materialdiffuses into the fiber ply/layer and is not simply on a surface of theply/layer. Any appropriate application method may be utilized to applythe polymeric binder material and particular use of a term such as“coated” is not intended to limit the method by which it is applied ontothe filaments/fibers. Useful methods include, for example, spraying,extruding or roll coating polymers or polymer solutions onto the fibers,as well as transporting the fibers through a molten polymer or polymersolution. Most preferred are methods that substantially coat orencapsulate each of the individual fibers and cover all or substantiallyall of the fiber surface area with the polymeric binder material.

As previously stated, each of the fibrous materials, including thefirst, second and third fibrous materials, may comprise woven fabrics,non-woven fabrics formed from unidirectionally oriented fibers,non-woven felted fabrics formed from randomly oriented fibers, orknitted fabrics. Woven fabrics may be formed using techniques that arewell known in the art using any fabric weave, such as plain weave,crowfoot weave, basket weave, satin weave, twill weave, threedimensional woven fabrics, and any of their several variations. Plainweave is most common, where fibers are woven together in an orthogonal0°/90° orientation, and is preferred. More preferred are plain weavefabrics having an equal warp and weft count. In one embodiment, a singlelayer of woven fabric preferably has from about 15 to about 55fiber/yarn ends per inch (about 5.9 to about 21.6 ends per cm) in boththe warp and fill directions, and more preferably from about 17 to about45 ends per inch (about 6.7 to about 17.7 ends per cm). The fibers/yarnsforming the woven fabric preferably have a denier of from about 375 toabout 1300. The result is a woven fabric weighing preferably from about5 to about 19 ounces per square yard (about 169.5 to about 644.1 g/m²),and more preferably from about 5 to about 11 ounces per square yard(about 169.5 to about 373.0 g/m²). Examples of such woven fabrics arethose designated as SPECTRA® fabric styles 902, 903, 904, 952, 955 and960 available from JPS Composite Materials of Anderson, S.C. or othercommercial weavers, fabricated with SPECTRA® fibers from HoneywellInternational Inc. Other exemplary woven fabrics include fabrics formedfrom basket weaves, such as SPECTRA® fabric style 912. Examples ofaramid-based woven fabrics are those designated as KEVLAR® fabric styles704, 705, 706, 708, 710, 713, 720, 745 and 755 available from DuPont andTWARON® fabric styles 5704, 5716 and 5931, which are commerciallyavailable from Kolon Industries, Inc.

Knit fabric structures are constructions composed of intermeshing loops,with the four major types being tricot, raschel, net and orientedstructures. Due to the nature of the loop structure, knits of the firstthree categories are not as suitable as they do not take full advantageof the strength of a fiber. Oriented knitted structures, however, usestraight inlaid yarns held in place by fine denier knitted stitches. Thefibers are very straight without the crimp effect found in woven fabricsdue to the interlacing effect on the yarns. These laid in yarns can beoriented in a monoaxial, biaxial or multi-axial direction depending onthe engineered requirements. It is preferred that the specific knitequipment used in laying in the load bearing yarns is such that theyarns are not pierced through.

Felts may also be formed by one of several techniques known in the art,such as by carding or fluid laying, melt blowing and spin laying. A feltis a non-woven network of randomly oriented fibers, preferably at leastone of which is a discontinuous fiber, preferably a staple fiber havinga length ranging from about 0.25 inch (0.64 cm) to about 10 inches (25.4cm).

A non-woven unidirectional fibrous ply of the invention may be formed byconventional methods in the art. For example, in a preferred method offorming a non-woven unidirectional fibrous ply, a plurality of fibersare arranged into an array, typically being arranged as a fiber webcomprising a plurality of fibers aligned in a substantially parallel,unidirectional array. In a typical process, fiber bundles are suppliedfrom a creel and led through guides and one or more spreader bars into acollimating comb. This is typically followed by coating the fibers witha polymeric binder material. A typical fiber bundle will have from about30 to about 2000 individual fibers. The spreader bars and collimatingcomb disperse and spread out the bundled fibers, reorganizing themside-by-side in a coplanar fashion. Ideal fiber spreading results in theindividual filaments or individual fibers being positioned next to oneanother in a single fiber plane, forming a substantially unidirectional,parallel array of fibers without fibers overlapping each other. Similarto woven fabrics, a single ply of woven fabric preferably has from about15 to about 55 fiber/yarn ends per inch (about 5.9 to about 21.6 endsper cm), and more preferably from about 17 to about 45 ends per inch(about 6.7 to about 17.7 ends per cm). Next, if the fibers are to becoated with a matrix/binder, the coating is applied according toconventional methods and is then typically dried followed by forming thecoated fibers into a single-ply of a desired length and width. Uncoatedfibers may be bound together with an adhesive film, by bonding thefibers together with heat, or any other known method, to thereby form asingle-ply.

Whether unidirectional non-woven, felted non-woven, woven or knitted, aplurality of fibrous plies may be merged together according toconventional methods in the art to form each individual section of theballistic resistant composite. In this regard, a plurality of singleplies of the selected fabric/fibrous ply type are stacked on top of eachother in coextensive fashion and merged, i.e. consolidated, together.When a section (e.g. the first fibrous material, or the second fibrousmaterial, or the third fibrous material, etc.) comprises feltednon-woven, woven or knitted fibrous plies, each section of fibrousmaterial preferably includes from about 2 to about 100 fibrous plies,more preferably from about 2 to about 85 fibrous plies, and mostpreferably from about 2 to about 65 fibrous plies. When a sectioncomprises a plurality of unidirectional non-woven fibrous plies, it istypical for a plurality of such plies to first be formed into a 2-ply or4-ply unidirectional non-woven fiber “layer,” also referred to in theart as a “pre-preg,” prior to combining a plurality of such “layers” or“pre-pregs” together to form the section. Each “layer” or “pre-preg”typically includes from 2 to about 6 fibrous plies, typically beingcross-plied at 0°/90°, but may include as many as about 10 to about 20fibrous plies as may be desired for various applications, with thelayers also being cross-plied at alternating 0°/90° orientations. When asection (e.g. the first fibrous material, or the second fibrousmaterial, or the third fibrous material, etc.) comprises such non-wovenunidirectional fiber “layers,” the section preferably comprises from 2to about 100 fiber layers, more preferably from about 2 to about 85fiber layers, and most preferably from about 2 to about 65 fiber layers.The total number of fibrous plies in each of the first fibrous material,second fibrous material, optional third fibrous material and anyadditional fibrous materials may be different or may be the same,wherein the layers are of any suitable thickness. The greater the numberof total plies in a section translates to greater ballistic resistance,but also greater weight.

With particular regard to fibrous materials comprising unidirectionalnon-woven fibrous plies, it is conventionally known in the art thatexcellent ballistic resistance is achieved when the individual fibrousplies are coextensively stacked upon each other are cross-plied suchthat the such that the unidirectionally oriented fibers in each fibrousply are oriented in a non-parallel longitudinal fiber direction relativeto the longitudinal fiber direction of each adjacent ply. Mostpreferably, the fibrous plies are cross-plied orthogonally at 0° and 90°angles wherein the angle of the fibers in even numbered layers ispreferably substantially the same and the angle of the fibers in oddnumbered layers is preferably substantially the same, but adjacent pliescan be aligned at virtually any angle between about 0° and about 90°with respect to the longitudinal fiber direction of another ply. Forexample, a five ply non-woven structure may have plies oriented at a0°/45°/90°/45°/0° or at other angles. Such rotated unidirectionalalignments are described, for example, in U.S. Pat. Nos. 4,457,985;4,748,064; 4,916,000; 4,403,012; 4,623,574; and 4,737,402, all of whichare incorporated herein by reference to the extent not incompatibleherewith. Typically, the fibers in adjacent plies will be oriented at anangle of from 45° to 90°, preferably 60° to 90°, more preferably 80° to90° and most preferably at about 90° relative to each other.

Each of the first fibrous material, second fibrous material, optionalthird fibrous material and any additional fibrous materials may beformed from identical fiber types or different fiber types, and mayinclude the same matrix/binder type or different matrix/binder types. Inone embodiment, the fibers and polymeric binder forming the firstfibrous material are both chemically the same as the fibers andpolymeric binder forming the second fibrous material. For example, eachfibrous material may comprise ultra-high molecular weight polyethylenefibers coated with a polyurethane binder. In another embodiment, thefibers and polymeric binder forming the first fibrous material are bothchemically different than the fibers and polymeric binder forming thesecond fibrous material. For example, the first fibrous material maycomprise ultra-high molecular weight polyethylene fibers coated with apolyurethane binder while the second composite comprise aramid fiberscoated with a polystyrene-polyisoprene-polystyrene block copolymerbinder.

In a preferred three fibrous section article embodiment (1^(st) fibrousmaterial/2^(nd) fibrous material/3^(rd) fibrous material), each of thefirst fibrous material and the second fibrous material comprise fiberscoated with a polymeric binder, wherein the fibers and the binderforming the first fibrous material are both chemically the same as thefibers and binder forming the second fibrous material, with the fibersof the second fibrous material having a lower tenacity. However, thethird fibrous material is preferably comprised of fibers that arechemically different than the fibers of each of the first and secondfibrous materials, which fibers have a lower tenacity than the fibers ofboth the first fibrous material and the second fibrous material. In saidembodiment, the third fibrous material may also include a polymericbinder that is either chemically the same as or chemically differentthan the binder of each of the other fibrous material sections. Forexample, the first fibrous material may comprise aramid fiber basedfibrous plies coated with a polyurethane based binder, the secondfibrous material may comprise aramid fiber based fibrous plies coatedwith a polyurethane based binder, and the third fibrous material maycomprise nylon fibers coated with a polyurethane based binder. Inanother example, the first fibrous material may comprise polyethylenefiber based fibrous plies coated with a polyurethane based binder, thesecond fibrous material may comprise polyethylene fiber based fibrousplies coated with a polyurethane based binder, and the third fibrousmaterial may comprise nylon fibers coated with a polyurethane basedbinder.

The sections of fibrous material individually may be the same ordifferent in fabric structure (e.g., woven, knitted, unidirectionalnon-woven or felted non-woven) relative to each other. Most preferably,the ballistic resistant articles are formed by a combination ofdifferent types of fabrics forming a hybrid structure. In one preferredembodiment, a three section composite is formed wherein all of thefibrous plies of the first fibrous material are woven plies, all thefibrous plies of the second fibrous material are unidirectionalnon-woven plies, and all of the fibrous plies of the third fibrousmaterial are woven plies. In another preferred embodiment, all of thefibrous plies of the first fibrous material are woven plies, all thefibrous plies of the second fibrous material are unidirectionalnon-woven plies, and all of the fibrous plies of the third fibrousmaterial are felted non-woven plies. In yet another preferredembodiment, all of the fibrous plies of the first fibrous material areunidirectional non-woven plies, all the fibrous plies of the secondfibrous material are woven plies, and all of the fibrous plies of thethird fibrous material are unidirectional non-woven plies.

In still other embodiments, some fibrous material sections may comprisea greater amount of polymeric binder than other fibrous materialsections, or some fibrous material sections may comprise a polymericbinder while other fibrous material sections have no polymeric binder(i.e. are matrix-free). In one preferred three fibrous material sectionembodiment, the second fibrous material section has greater polymericbinder content than the first fibrous material section. This embodimentwill increase the stiffness of the second fibrous material section totherefore reduce trauma. The third fibrous material in this embodimentmay or may not include a polymeric binder.

The type and number of fibrous plies affects the areal density of aballistic resistant composite article, and the total number of fibrousplies in a ballistic resistant article provided herein will varydepending upon the ultimate end use of the article. For example, in bodyarmor vests for military applications, in order to form an article thatachieves an areal density of 1.0 lb/ft² (psf) (4.88 kg/m² (ksm)), atotal of at 22 individual 2-ply (e.g.)0°/90° layers may be required.Minimum levels of body armor ballistic resistance for military use arecategorized by National Institute of Justice (NIJ) Threat Levels, as iswell known in the art.

Each fibrous material section of the invention has an areal density ofat least 100 g/m², preferably having an areal density of at least 200g/m² and more preferably having an areal density of at least 976 g/m².In preferred embodiments, the sum of the first fibrous material, secondfibrous material, a third fibrous material or non-fibrous third section,and any additional fibrous materials produces a ballistic resistantmaterial having a total combined areal density of from about 0.5 psf(2.44 ksm) to about 8.0 psf (39.04 ksm), more preferably from about 0.5psf (2.44 ksm) to about 5.0 psf (24.4 ksm), still more preferably fromabout 0.5 psf (2.44 ksm) to about 3.5 psf (17.08 ksm), still morepreferably from about 0.75 psf (3.66 ksm) to about 3.0 psf (14.64 ksm),still more preferably from about 0.75 psf (3.66 ksm) to about 1.5 psf(7.32 ksm), and most preferably from about 0.9 psf (4.392 ksm) to about1.5 psf (7.32 ksm).

As previously stated, in use, the first fibrous material section ispreferably positioned as the front “strike face” section of theballistic resistant material, i.e. the section that a projectile threatwill strike first. For maximum backface signature resistanceperformance, when the first fibrous material is positioned as the strikeface section, this first section preferably has an areal density ofgreater than 50% of the total combined areal density of the entirecomposite article. In one embodiment, the areal density of the firstfibrous material section is greater than about 60% of the total combinedareal density of all combined sections. In another embodiment, the arealdensity of the first fibrous material section is greater than about 70%of the total combined areal density of all combined sections. In mostpreferred embodiments, the first fibrous material section comprises fromabout 60% to about 75% of the total combined areal density of all thecomposite article sections combined, the second fibrous materialcomprises from about 20% to about 30% of the total combined arealdensity of all the composite article sections, and the third section(fibrous or not) comprises from about 5% to about 10% of the totalcombined areal density of all the composite article sections. In anotherembodiment, the areal density of the first composite may be equal to theareal density of the second composite. In a preferred three composite(1^(st)/2^(nd)/3^(rd)) article, the first and third composites combinedcomprise from about 60% to about 75% of the total combined areal densityand the second composite comprises from about 25% to about 40% of thetotal combined areal density. In a specifically preferred three fibrouscomposite (1^(st)/2^(nd)/3^(rd)) configuration, the first and thirdcomposites combined comprise about 75% of the total combined arealdensity and the second composite comprises about 25% of the totalcombined areal density. In another specifically preferred three fibrouscomposite (1^(st)/2^(nd)/3^(rd)) configuration, the first and thirdcomposites combined comprise about 63% of the total combined arealdensity and the second composite comprises about 37% of the totalcombined areal density. These asymmetrical, unbalanced configurationsare specifically preferred because they exhibit a combination ofsuperior ballistic penetration resistance and maximum backface signatureresistance performance.

The thickness of each fibrous material section will correspond to thethickness of the individual fibers and the number of fiber plies/layersincorporated into the composite. For example, a preferred wove fabric,knitted fabric or felted non-woven fabric will have a preferredthickness of from about 25 μm to about 600 μm per ply/layer, morepreferably from about 50 μm to about 385 μm and most preferably fromabout 75 μm to about 255 μm per ply/layer. A preferred two-plyunidirectional non-woven fabric composite will have a preferredthickness of from about 12 μm to about 600 μm, more preferably fromabout 50 μm to about 385 μm and most preferably from about 75 μm toabout 255 μm. A preferred isotropic polymer sheet or metal sheet willhave a preferred thickness of from about 12 μm to about 600 μm, morepreferably from about 75 μm to about 385 μm and most preferably fromabout 125 μm to about 255 μm.

When forming the articles provided herein, all the plies comprising allof the different section may be overlapped on top of each other to forma stack followed by consolidating the plurality of layers together atonce, or each section may first be consolidated individually followed bymerging the consolidated sections together. Merging of the fibrouslayers and sections into single-layer composite structures may beaccomplished using conventional techniques in the art, such asconsolidation or molding techniques. In this regard, merging using nopressure or low pressure is often referred to in the art as“consolidation” while high pressure merging is often referred to as“molding,” but these terms are also frequently used interchangeably.

In the preferred embodiments, each stack of overlapping non-woven fiberplies (unidirectional or felted), woven fabric plies, knitted fabricplies or a combination thereof is merged under heat and pressure, or byadhering the coatings of individual fibrous plies to each other, tothereby form a single-layer, monolithic element. Methods ofconsolidating fibrous plies/layers are well known, such as by themethods described in U.S. Pat. No. 6,642,159. Consolidation can occurvia drying, cooling, heating, pressure or a combination thereof. Heatand/or pressure may not be necessary, as the fibers or fibrous plies mayjust be glued together with an adhesive as is the case in a wetlamination process. Consolidation may be performed at temperaturesranging from about 50° C. to about 175° C., preferably from about 105°C. to about 175° C., and at pressures ranging from about 5 psig (0.034MPa) to about 2500 psig (17 MPa), for from about 0.01 seconds to about24 hours, preferably from about 0.02 seconds to about 2 hours. Whenheating, it is possible that a present polymeric binder coating can becaused to stick or flow without completely melting. However, generally,if the polymeric binder material is caused to melt, relatively littlepressure is required to form the composite, while if the binder materialis only heated to a sticking point more pressure is typically required.As is conventionally known in the art, consolidation may be conducted ina calender set, a flat-bed laminator, a press or in an autoclave.Consolidation may also be conducted by vacuum molding the material in amold that is placed under a vacuum. Vacuum molding technology is wellknown in the art. Most commonly, a plurality of orthogonal fiber websare “glued” together with the binder polymer and run through a flat-bedlaminator to improve the uniformity and strength of the bond.

Alternately, merging of the fibrous plies may be achieved by moldingunder heat and pressure in a suitable molding apparatus. Generally,molding is conducted at a pressure of from about 50 psi (344.7 kPa) toabout 5,000 psi (34,470 kPa), more preferably about 100 psi (689.5 kPa)to about 3,000 psi (20,680 kPa), most preferably from about 150 psi(1,034 kPa) to about 1,500 psi (10,340 kPa). Molding may alternately beconducted at higher pressures of from about 5,000 psi (34,470 kPa) toabout 15,000 psi (103,410 kPa), more preferably from about 750 psi(5,171 kPa) to about 5,000 psi, and more preferably from about 1,000 psito about 5,000 psi. The molding step may take from about 4 seconds toabout 45 minutes. Preferred molding temperatures range from about 200°F. (˜93° C.) to about 350° F. (˜177° C.), more preferably at atemperature from about 200° F. to about 300° F. and most preferably at atemperature from about 200° F. to about 280° F. The pressure under whichthe fibrous plies are molded has a direct effect on the stiffness orflexibility of the resulting molded product. Particularly, the higherthe pressure at which they are molded, the higher the stiffness, andvice-versa. In addition to the molding pressure, the quantity, thicknessand composition of the fibrous plies and polymeric binder coating typealso directly affects the stiffness of composite.

While each of the molding and consolidation techniques described hereinare similar, each process is different. Particularly, molding is a batchprocess and consolidation is a generally continuous process. Further,molding typically involves the use of a mold, such as a shaped mold or amatch-die mold when forming a flat panel, and does not necessarilyresult in a planar product. Normally consolidation is done in a flat-bedlaminator, a calendar nip set or as a wet lamination to produce soft(flexible) body armor fabrics. Molding is typically reserved for themanufacture of hard armor, e.g. rigid plates. In either process,suitable temperatures, pressures and times are generally dependent onthe type of polymeric binder coating materials, polymeric bindercontent, process used and fiber type.

Alternative consolidation methods are also applicable when merging aplurality of woven fabrics, knitted fabrics or felted non-woven fabrics.For example, a plurality of woven fabrics may be interconnected witheach other using 3D weaving methods, such as by weaving warp and weftthreads into a stack of woven fabrics both horizontally and vertically.A plurality of woven or non-woven fabrics may also be attached to eachother by mechanical attachment such as stitching/needle punching fabricstogether in the z-direction. Similar techniques may be employed formerging a plurality of knitted fabrics. Felted fibrous plies may beconsolidated mechanically such as by needle punching, stitch-bonding,hydro-entanglement, air entanglement, spin bonding, spin lacing or thelike, chemically such as with an adhesive, or thermally with a fiber topoint bond or a blended fiber with a lower melting point. The preferredconsolidation method is needle punching alone or followed by one of theother methods. The preferred felt is a needle punched felt.

When the fibrous plies or sections of fibrous plies are attached to eachother with an intermediate, suitable adhesives non-exclusively includeelastomeric materials such as polyethylene, cross-linked polyethylene,chlorosulfonated polyethylene, ethylene copolymers, polypropylene,propylene copolymers, polybutadiene, polyisoprene, natural rubber,ethylene-propylene copolymers, ethylene-propylene-diene terpolymers,polysulfide polymers, polyurethane elastomers, polychloroprene,plasticized polyvinylchloride using one or more plasticizers that arewell known in the art (such as dioctyl phthalate), butadieneacrylonitrile elastomers, poly (isobutylene-co-isoprene), polyacrylates,polyesters, unsaturated polyesters, polyethers, fluoroelastomers,silicone elastomers, copolymers of ethylene, thermoplastic elastomers,phenolics, polybutyrals, epoxy polymers, styrenic block copolymers, suchas styrene-isoprene-styrene or styrene-butadiene-styrene types, andother suitable adhesive compositions conventionally known in the art.Particularly preferred adhesives include methacrylate adhesives,cyanoacrylate adhesives, UV cure adhesives, urethane adhesives, epoxyadhesives and blends of the above materials. Of these, an adhesivecomprising a polyurethane thermoplastic adhesive, particularly a blendof one or more polyurethane thermoplastics with one or more otherthermoplastic polymers, is preferred. Most preferably, the adhesivecomprises polyether aliphatic polyurethane. Such adhesives may beapplied, for example, in the form of a hot melt, film, paste or spray,or as a two-component liquid adhesive.

The individual plies of individual fibrous material sections may also bejoined together by other suitable means for direct attachment such asstitching, bolting, screwing or needle punching, such that theirsurfaces contact each other, or a combination of any of the abovemethods. The individual plies of each individual section may also remainunconsolidated, followed by consolidating/molding a unit comprisingmultiple unconsolidated composite sections together in a single step,optionally wherein each of the individual sections are stitched togetherto maintain their integrity prior to the single unitaryconsolidation/molding step.

Regardless of the method used to join the plies of each individualsection, all of the sections of the composite article are to be bondedtogether by high pressure molding or consolidation with an intermediatepolymer layer or adhesive, or by employing an existing polymeric bindercoating as an adhesive to aid in bonding the different sectionstogether, to thereby form a consolidated, unitary composite article.This specifically excludes stitching as a sole means of attaching thedifferent sections together. It has been found that bonding the sectionstogether by molding or adhesive consolidation will increaseinter-laminar strength between the different sections, which translatesto higher stiffness and reduced trauma, i.e. improved backface signatureperformance.

The ballistic resistant composites of the invention may also optionallycomprise one or more thermoplastic polymer layers attached to one orboth of their outer surfaces. Suitable polymers for the thermoplasticpolymer layer non-exclusively include polyolefins, polyamides,polyesters (particularly polyethylene terephthalate (PET) and PETcopolymers), polyurethanes, vinyl polymers, ethylene vinyl alcoholcopolymers, ethylene octane copolymers, acrylonitrile copolymers,acrylic polymers, vinyl polymers, polycarbonates, polystyrenes,fluoropolymers and the like, as well as co-polymers and mixturesthereof, including ethylene vinyl acetate (EVA) and ethylene acrylicacid. Also useful are natural and synthetic rubber polymers. Of these,polyolefin and polyamide layers are preferred. The preferred polyolefinis a polyethylene. Non-limiting examples of useful polyethylenes are lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE),medium density polyethylene (MDPE), linear medium density polyethylene(LMDPE), linear very-low density polyethylene (VLDPE), linear ultra-lowdensity polyethylene (ULDPE), high density polyethylene (HDPE) andco-polymers and mixtures thereof. Also useful are SPUNFAB® polyamidewebs commercially available from Spunfab, Ltd, of Cuyahoga Falls, Ohio(trademark registered to Keuchel Associates, Inc.), as well asTHERMOPLAST™ and HELIOPLAST™ webs, nets and films, commerciallyavailable from Protechnic S.A. of Cernay, France.

Any thermoplastic polymer layers are preferably very thin, havingpreferred layer thicknesses of from about 1 μm to about 250 μm, morepreferably from about 5 μm to about 25 μm and most preferably from about5 μm to about 9 μm. Discontinuous webs such as SPUNFAB® non-woven websare preferably applied with a basis weight of 6 grams per square meter(gsm). While such thicknesses are preferred, it is to be understood thatother thicknesses may be produced to satisfy a particular need and yetfall within the scope of the present invention.

Such thermoplastic polymer layers may be bonded to the compositesurfaces using well known techniques, such as thermal lamination.Typically, laminating is done by positioning the individual layers onone another under conditions of sufficient heat and pressure to causethe layers to combine into a unitary structure. Lamination may beconducted at temperatures ranging from about 95° C. to about 175° C.,preferably from about 105° C. to about 175° C., at pressures rangingfrom about 5 psig (0.034 MPa) to about 100 psig (0.69 MPa), for fromabout 5 seconds to about 36 hours, preferably from about 30 seconds toabout 24 hours. Such thermoplastic polymer layers may alternatively bebonded to the composite surfaces with hot glue or hot melt fibers aswould be understood by one skilled in the art.

In use, the multi-section ballistic resistant composite articles may beprovided with a cover into which the materials are positioned. Soft bodyarmor covers include woven fabrics, for example, woven fabrics made fromnylon, cotton, and/or other fibers. One particularly preferred covermaterial is a rip stop woven fabric, preferably a rip stop woven nylonfabric which is formed from 70 denier nylon fibers having a weight of 95g/m² and is typically coated with a polyurethane resin on at least oneits surfaces. Such fabrics are known in the art and are typically madeby weaving nylon threads throughout a base material in interlockingpatterns. These fabrics are very resistant to tearing and ripping. Thecover may be sealed closed via conventional means in the art, such asstitching. The cover may alternatively be formed from a material thatcan be welded or heat sealed, which is of particular interest wherebarrier properties are desired, such as moisture or solvent barriers.The consolidated, unitary, multi-section composite article may or maynot be bonded to the optional cover. In one exemplary embodiment where athree-section composite article is positioned in a cover, either looselyor where the article is bonded to the cover, the third fibrous materialsection may be formed from nylon fibers such that a section of nylonfibers is included within a cover that is also made from nylon fibers.

The ballistic resistant composites provided herein may be used to formarticles having superior ballistic penetration resistance. Articleshaving superior ballistic penetration resistance are those which exhibitexcellent properties defending against penetration by deformableprojectiles, such as bullets, and against penetration of fragments, suchas shrapnel. The ballistic resistant composites are also suitable forbody armor applications that require low backface deformation, i.e.optimal blunt trauma resistance, including flexible, soft armor articlesas well as rigid, hard armor articles, as well as for the defense ofvehicles and structural elements, such as building walls.

The following examples serve to illustrate the invention.

EXAMPLES 1-4

Four different types of shoot packs were prepared from the materialsidentified below and tested for ballistic penetration resistance andbackface signature performance:

Materials

1. GOLD FLEX®

GOLD FLEX®, commercially available from Honeywell International Inc. ofMorristown, N.J., is a highly flexible four-ply unidirectional non-wovenfabric formed from aramid fibers having a breaking tenacity of 2350mN/tex. The fibers in each ply are parallel to each other and areoriented orthogonally relative to the fibers in each adjacent ply(conventional 0°/90°/0°/90° construction). The fibers are coated with apolyisoprene-polystyrene-block copolymer based binder resin. The fouraramid plies were laminated between two linear low density polyethylene(LLDPE) films, each having a thickness of 9 μm and an areal density of 8g/m², positioning said LLDPE layers on both outer surfaces of thefabric.

2. GOLD SHIELD® GA-2010

GOLD SHIELD® GA-2010, commercially available from HoneywellInternational Inc., is a highly flexible two-ply unidirectionalnon-woven fabric formed from aramid fibers having a breaking tenacity of2025 mN/tex. The fibers in each ply are parallel to each other and areoriented orthogonally relative to the fibers in each adjacent ply(conventional 0°/90° construction). The fibers are coated with apolyisoprene-polystyrene-block copolymer based binder resin. The twoaramid plies were laminated between two linear low density polyethylene(LLDPE) films, each having a thickness of 9 μm and an areal density of 8g/m², positioning said LLDPE layers on both outer surfaces of thefabric.

3. Nylon Fabric

A 26×26 plain weave woven fabric formed with nylon fibers having atenacity below 800 mN/tex and a denier of 840. The fabric has an arealdensity of 200 g/m².

Ballistic Testing Methods

Each shoot pack identified below was tested for ballistic performanceagainst a 9 mm Full Metal Jacket Remington bullet. Each shoot pack wasmounted on a steel test frame measuring 610 mm×610 mm×140 mm±2 mm andheld in place with stretchable 2″ wide bands. The steel frame was filledand compacted with Roma Plastilina #1 clay as recommended by NIJ 0101.04and NIJ 0101.06. The steel frame was mounted at a 90° orientation to theline of bullets being fired from a firmly mounted universal receiver.Before testing, the clay inside steel frame was calibrated to meet theNIJ 0101.04 and NIJ 0101.06 standards.

To achieve National Institute of Justice NIJ0101.04 and NIJ0101.06compliance of a vest and shoot pack construction, each materialconstruction must successfully complete a two-part performance testseries, one for ballistic penetration resistance and the other forbackface signature performance.

Backface Signature Test

The standard method for measuring BFS of soft armor is outlined by NIJStandard 0101.04, Type IIIA, where an armor sample is place in contactwith the surface of the deformable Roma Plastilina #1 clay. This NIJmethod is conventionally used to obtain a reasonable approximation orprediction of actual BFS that may be expected during a ballistic eventin field use for armor that rests directly on or very close to the bodyof the user. In this test, the depth of a non-penetrating projectileimpact in the clay must be 44 mm or less to pass.

V₅₀ Projectile Penetration Resistance Test

V₅₀ data was acquired taken under conventionally known standardizedtechniques, particularly per the conditions of Department of DefenseTest Method Standard MIL-STD-662F. The V₅₀ ballistic limit testing is astatistical test that experimentally identifies the velocity at which abullet has a 50 percent chance of penetrating the flexible shoot pack.Testing is conducted to achieve a V₅₀ value within ±15 msec based on anaverage of at least eight bullets fired on each shoot pack where 4bullets completely penetrate the shoot pack and 4 bullets partiallypenetrate the shoot pack.

Example 1 (Comparative)

Three identical 40 cm×40 cm square ballistic shoot packs were assembledby forming a stack of 18 overlapping layers of the four-ply GOLD FLEX®fabric specified above. During assembly all of the layers were alignedso that the orientation of the fibers in alternating plies remainedorthogonal (0°, 90°, 0°, 90°, (0°, 90°, 0°, 90°), etc., wherein thefibers of all the odd plies were in parallel with each other and thefibers of all the even plies of the shoot pack were in parallel witheach other. After stacking all of the 18 total layers, the layers weretack stitched on each of the four corners of the stack and placed into arip stop nylon cover for ballistic testing. The results of all testingis summarized in Table 1.

TABLE 1 Areal Backface Material 1 Material 2 Material 3 Density V₅₀Signature (# of layers) (# of layers) (# of layers) (kg/m²) (m/sec) (mm)18 0 0 4.20 492 39 18 0 0 4.20 486 38 18 0 0 4.20 484 38 Average 487 38

Example 2

Three identical 40 cm×40 cm square ballistic shoot packs were assembledby forming a stack of 5 overlapping layers of the four-ply GOLD FLEX®fabric specified above followed by 22 layers of the two-ply GOLD SHIELD®GA-2010 fabric specified above. During assembly all of the layers werealigned so that the orientation of the fibers in alternating pliesremained orthogonal (0°, 90°, 0°, 90°), (0°, 90°, 0°, 90°), etc.,wherein the fibers of all the odd plies were in parallel with each otherand the fibers of all the even plies of the shoot pack were in parallelwith each other. After stacking all of the 27 total layers, the layerswere tack stitched on each of the four corners of the stack and placedinto a rip stop nylon cover for ballistic testing. The results of alltesting is summarized in Table 2.

TABLE 2 Areal Backface Material 1 Material 2 Material 3 Density V₅₀Signature (# of layers) (# of layers) (# of layers) (kg/m²) (m/sec) (mm)5 22 0 4.34 469 33 5 22 0 4.34 466 32 5 22 0 4.34 468 39 Average 468 35

Example 3

Three identical 40 cm×40 cm square ballistic shoot packs were assembledby forming a stack of 5 overlapping layers of the four-ply GOLD FLEX®fabric specified above followed by 9 layers of the two-ply GOLD SHIELD®GA-2010 fabric specified above and 12 layers of the nylon woven fabricspecified above. During assembly all of the layers were aligned so thatthe orientation of the fibers in alternating plies remained orthogonal(0°, 90°, 0°, 90°), (0°, 90°, 0°, 90°), etc., for each of the GOLD FLEX®and GOLD SHIELD® GA-2010, wherein the fibers of all the odd plies werein parallel with each other and the fibers of all the even plies of theshoot pack were in parallel with each other. For the nylon fabriclayers, the longitudinal fiber direction of the weft fibers and the warpfibers, respectively, were kept parallel to the 0°/90° directions of thefibers of the GOLD FLEX® and GOLD SHIELD® GA-2010 plies. After stackingall of the 26 total layers, the layers were tack stitched on each of thefour corners of the stack and placed into a rip stop nylon cover forballistic testing. The results of all testing is summarized in Table 3.

TABLE 3 Areal Backface Material 1 Material 2 Material 3 Density V₅₀Signature (# of layers) (# of layers) (# of layers) (kg/m²) (m/sec) (mm)5 9 12 4.83 455 33 5 9 12 4.83 453 34 5 9 12 4.83 458 33 Average 455 33

Example 4

Three identical 40 cm×40 cm square ballistic shoot packs were assembledby forming a stack of 5 overlapping layers of the four-ply GOLD FLEX®fabric specified above followed by 9 layers of the two-ply GOLD SHIELD®GA-2010 fabric specified above and 14 layers of the nylon woven fabricspecified above. During assembly all of the layers were aligned so thatthe orientation of the fibers in alternating plies remained orthogonal(0°, 90°, 0°, 90°), (0°, 90°, 0°, 90°), etc., for each of the GOLD FLEX®and GOLD SHIELD® GA-2010, wherein the fibers of all the odd plies werein parallel with each other and the fibers of all the even plies of theshoot pack were in parallel with each other. For the nylon fabriclayers, the longitudinal fiber direction of the weft fibers and the warpfibers, respectively, were kept parallel to the 0°/90° directions of thefibers of the GOLD FLEX® and GOLD SHIELD® GA-2010 plies. After stackingall of the 28 total layers, the layers were tack stitched on each of thefour corners of the stack and placed into a rip stop nylon cover forballistic testing. The results of all testing is summarized in Table 3.

TABLE 4 Areal Backface Material 1 Material 2 Material 3 Density V₅₀Signature (# of layers) (# of layers) (# of layers) (kg/m²) (m/sec) (mm)5 9 14 7.42 469 33 5 9 14 7.42 466 32 5 9 14 7.42 468 39 Average 468 35

Conclusions

Examples 2, 3 and 4 illustrate that hybrid materials assembled such thatthe highest tenacity fibrous material is positioned as the strike facewhich first engages the projectile, followed by a second lower tenacityfibrous material and still lower tenacity third material, will achieveexcellent ballistic penetration resistance and backface signatureperformance at a lower cost than a composite formed from a singlematerial as in Example 1. The first material deforms, fragments andslows down the projectile bullet, and that deformed and fragmentedprojectile should stop in either the first section or second section offibrous material. The third material section supports the first twosections of material and distributes the energy which causes backfacedeformation to a wide area. Since this third set of material is not needto deform and slow down the projectile and projectile fragments, it canbe formed from fibers having a lower breaking tenacity or be anon-fibrous material, such as an energy mitigating material.

While the present invention has been particularly shown and describedwith reference to preferred embodiments, it will be readily appreciatedby those of ordinary skill in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe invention. It is intended that the claims be interpreted to coverthe disclosed embodiment, those alternatives which have been discussedabove and all equivalents thereto.

What is claimed is:
 1. A ballistic resistant composite comprising: afirst fibrous material comprising one or more first fibrous plies, eachof the first fibrous plies comprising fibers that have a tenacity ofgreater than 27 g/denier; a second fibrous material attached to thefirst fibrous material, said second fibrous material comprising one ormore second fibrous plies, each of the second fibrous plies comprisingfibers that have a tenacity lower than the tenacity of the fibers of thefirst fibrous material; and a third fibrous material attached to thesecond fibrous material, said third fibrous material comprising one ormore third fibrous plies, each of the third fibrous plies comprisingfibers that have a tenacity lower than the tenacity of the fibers of thesecond fibrous material; wherein the first fibrous material, secondfibrous material and third fibrous material are bonded together and forma consolidated, unitary composite article.
 2. The ballistic resistantcomposite of claim 1 wherein each of the fibers of the first fibrousmaterial has a tenacity of 40 g/denier or more.
 3. The ballisticresistant composite of claim 1 wherein each of the fibers of the firstfibrous material has a tenacity of 45 g/denier or more.
 4. The ballisticresistant composite of claim 1 wherein each of the fibers of the secondfibrous material has a tenacity of at least 25% less than the tenacityof each of the fibers of the first fibrous material.
 5. The ballisticresistant composite of claim 1 wherein each of the fibers of the secondfibrous material has a tenacity of 21 g/denier or less.
 6. The ballisticresistant composite of claim 1 wherein each of the fibers of the thirdfibrous material has a tenacity of at least 25% less than the tenacityof each of the fibers of the second fibrous material.
 7. The ballisticresistant composite of claim 1 wherein the third fibrous materialcomprises nylon fibers, polyester fibers, polypropylene fibers,polyolefin fibers or a combination thereof.
 8. The ballistic resistantcomposite of claim 1 wherein the first fibrous material comprisesultra-high molecular weight polyethylene fibers, the second fibrousmaterial comprises either ultra-high molecular weight polyethylenefibers or aramid fibers or a combination thereof, and the third fibrousmaterial comprises nylon fibers.
 9. The ballistic resistant composite ofclaim 1 wherein the first fibrous material comprises a woven aramidfabric, the second fibrous material comprises a non-woven aramid fabric,and the third fibrous material comprises nylon fibers.
 10. The ballisticresistant composite of claim 1 wherein the first fibrous material is anon-woven fabric comprising a plurality of unidirectionally orientedfibers, the second fibrous material is a non-woven fabric comprising aplurality of unidirectionally oriented fibers, and the third fibrousmaterial is either a non-woven fabric comprising a plurality ofunidirectionally oriented fibers, a woven fabric, a knitted fabric or afelt.
 11. The ballistic resistant composite of claim 1 wherein the firstfibrous material is a woven fabric, the second fibrous material is awoven fabric, and the third fibrous material is either a non-wovenfabric comprising a plurality of unidirectionally oriented fibers, awoven fabric, a knitted fabric or a felt.
 12. The ballistic resistantcomposite of claim 1 further comprising a non-fibrous isotropic polymerlayer attached to the third fibrous material, wherein the first fibrousmaterial, second fibrous material, third fibrous material and thenon-fibrous isotropic polymer layer are bonded together and form aconsolidated, unitary composite article.
 13. The ballistic resistantcomposite of claim 1 wherein the fibers of the first fibrous materialand the fibers of the second fibrous material are substantially coatedwith a polymeric binder.
 14. A ballistic resistant composite comprising:a first fibrous material comprising one or more first fibrous plies,each of the first fibrous plies comprising fibers; a second fibrousmaterial attached to the first fibrous material, said second fibrousmaterial comprising one or more second fibrous plies, each of the secondfibrous plies comprising fibers that have a tenacity lower than thetenacity of the fibers of the first fibrous material; and a non-fibroussheet material attached to the second fibrous material; wherein thefirst fibrous material, second fibrous material and third fibrousmaterial are bonded together and form a consolidated, unitary compositearticle.
 15. The ballistic resistant composite of claim 14 wherein thenon-fibrous sheet material comprises a non-fibrous isotropic polymerlayer.
 16. The ballistic resistant composite of claim 14 wherein each ofthe fibers of the first fibrous material has a tenacity of 40 g/denieror more and wherein each of the fibers of the second fibrous materialhas a tenacity of at least 25% less than the tenacity of each of thefibers of the first fibrous material.
 17. The ballistic resistantcomposite of claim 14 wherein the first fibrous material is a non-wovenfabric comprising a plurality of unidirectionally oriented fibers andthe second fibrous material is a non-woven fabric comprising a pluralityof unidirectionally oriented fibers.
 18. The ballistic resistantcomposite of claim 14 wherein the first fibrous material is a wovenaramid fabric and the second fibrous material is a non-woven aramidfabric.
 19. A ballistic resistant composite comprising: a first fibrousmaterial comprising one or more first fibrous plies, each of the firstfibrous plies comprising fibers, wherein each of said fibers has atenacity of greater than 27 g/denier; a second fibrous material attachedto the first fibrous material, said second fibrous material comprisingone or more second fibrous plies, each of the second fibrous pliescomprising fibers, wherein each of said fibers has a tenacity of atleast 50% less than the tenacity of the fibers of the first fibrousmaterial; and a third fibrous material attached to the second fibrousmaterial, said third fibrous material comprising one or more thirdfibrous plies, each of the third fibrous plies comprising fibers,wherein each of said fibers has a tenacity of at least 50% less than thetenacity of the fibers of the second fibrous material; wherein the firstfibrous material, second fibrous material and third fibrous material arebonded together and form a consolidated, unitary composite article. 20.The ballistic resistant composite of claim 19 wherein the consolidated,unitary composite article has a total areal density of from about 0.75lb/ft² to about 1.5 lb/ft².